450D252KSD5 is a customizable potentiometer which has gone obsolete but DigiKey carries an alternative which differs only in actuator length. 450D252KSD6
This has an actuator length of 0.75" and the obsolete item had an actuator length of 0.625".
There are also other options in this series that also only differ in actuator length or style.
Rotary Potentiometers, Rheostats | Electronic Components Distributor DigiKey
If there are any questions on this, please reply to this post and we will be happy to address them.
Please review the datasheets to ensure the alternative will work for your application.