Collimazione primaria

Manopole: plastica nera, diametro 16 mm (5/8").

Filettature: acciaio inossidabile

Blocco primario

Manopole: plastica rossa, diametro 16 mm (5/8").

Filettature: acciaio inossidabile

Notes:
- The telescope optical tube assembly will clear the Dobsonian rocker box with primary knobs installed.
- Knobs with shorter screws and spacers replace the factory flathead Phillips collimation screws. Knobs with longer screws replace the factory set-style (grub) locking screws.
- Since the factory collimation and locking screws are close together, knobs must be staggered in height. The locking knobs protrude further than the collimation knobs, and they are now red in color.
- Some telescopes have a cover over the primary collimation screws. This cover must be removed and set aside when Bob's Knobs are installed.
- Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.