Baader T-2 VariLock Extension Tube – 20-29 mm

• Lockable T-2 extension tube, adjustable 20-29 mm with clamping
• Telescope-side connection dimension: T-2 (M42 x 0.75), Eyepiece connection dimension: Optional T-2 (M42 x 0.75) or T-2 Ring Schwalbe 52 x 6.5mm optical length: 20-29 mm continuously adjustable over millimeter scale
• Outer diameter: 50.8mm / 2 "inside diameter: with eyepiece side T-2 thread insert = 38mm with 52mm dovetail eyepiece sided = 42mm

Both Baader VariLock T-2 (M42x0.75mm) extensions are stepplessly adjustable extension rings, with the added ability to firmly readjust the camera rotation position. By loosening or tightening a locking ring, the inner extension sleeve can be adjusted to the desired length by means of a millimeter scale. A clamping key (hook wrench) for the locking ring is included. Both VariLocks 29 and 46 are the result of an otherwise fruitless search for adjustable extension rings that are absolutely torsion-resistant, because almost all so-called "helical fokusers" are not torsionally stiff.

As further application, the ring with the rotatable T-2 outer thread can be removed by loosening 6 headless set-screws (hexagonal wrench included) and replaced by a separately enclosed adapter with ringed-dovetail (ring-groove), whose 52 mm diameter dovetail can be inserted directly into all Baader T-rings for EOS, Protective for Canon, as well as NEX bayonet cameras – likewise into all other manufacturers standard T-rings with the appropriate 52 mm inner diameter to accommodate a rotating ring. This increases the VariLock clear inner diameter because the common bottleneck at the height of the T-2 thread is getting eliminated. By necessity, the maximum inner diameter of all T-2 adapters is 38mm as standard. On the other hand, the clear inner diameter at this point increases up to 42 mm if one uses the enclosed direct S52 adapter instead.

VariLocks are ideal tools for permanently setting exact focal distances, e.g. for H-alpha solar filters or field correctors/reducers with critical focal position.