Our online catalog is being updated! Please contact us for current pricing. VRS Series Viewport Shutters Thermionics manufactures a series of rotary-actuated shutter assemblies. They are of the 90° shutter swing type, suitable for mounting behind "zero height" viewports. VRS Series shutters are built into double-sided flanges. Rotary actuation is supplied by our FRMC-133-25 rotary feedthrough (included). This supplies positive mechanical control of shutter position and does not introduce stray magnetic fields. This also makes a number of drive options available at competitive prices. The standard unit includes a position lock. Specifications Double-sided flange mount Suitable for mounting behind viewport on tube neck All metal sealed Actuated with attached FRMC with position lock All stainless steel ball bearing construction Attached shutter covers >80° of standard viewport window Protects viewport from depositing materials Ordering Information -- Rotary-Actuated Viewport Shutters Mounting Flange O.D. A B C Model No. Price 2.75" 6.05" 0.53" .750" VRS-275 $1,050. 4.50" 6.66" 1.16" .687" VRS-450 $1,200. 4.63" 6.69" 1.22" .812" VRS-463 $1,300. 6.00" 7.10" 1.78" .781" VRS-600 $1,400. 8.00" 8.31" 2.53" .875" VRS-800 $1,650. NOTE: Sliding shutters with and without housings are available. OPTIONS /MS Stepping or /MY Synchronous Motorized Rotary Feedthrough Uses FRM-133-25 rotary feedthrough Integral motor drive /MS stepping or /MY synchronous motor 50 oz-in holding torque (high torque motors available) Low inertia design Manual knob Price      $525. /LSA-90 Limit Switch Package Allows 90° actuation of FRM Price      $235. For 110 VAC use Price      $55. /MS/W or/MY/W Motorized Rotary--Self-Locking Uses FRM-133-25 rotary feedthrough High speed worm drive Self-locking /MS stepping or /MY synchronous motor Supplied with motor without controller Can be retrofitted May be field mounted without breaking vacuum or returned to the factory for installation Price      $1,035. /PNM Pneumatically Operated 1/4" O.D. output shaft Bellows sealed Torque limit: 150 oz-in 90° rotation Adjustable stops available Price      $480. /ACV-24 Air Control Valve Option Mounted to feedthrough Valve to actuator plumbing installed Control voltage 24 VDC standard or per customer requirements With flow controls, both directions Price      $115