# ObserverManager<TIdentity, TObserver> Properties

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.utilities.observermanager-2/)

## Count {#count-46fffd77}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.utilities.observermanager-2/properties/count-46fffd77/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core/Utils/ObserverManager.cs#L88)

```csharp
public int ObserverManager<TIdentity, Count
```

Gets the number of observers.

## ExpirationDuration {#expirationduration-cdff8471}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.utilities.observermanager-2/properties/expirationduration-cdff8471/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core/Utils/ObserverManager.cs)

```csharp
public TimeSpan ObserverManager<TIdentity, ExpirationDuration
```

Gets or sets the expiration time span, after which observers are lazily removed.

## GetDateTime {#getdatetime-a9e256ab}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.utilities.observermanager-2/properties/getdatetime-a9e256ab/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core/Utils/ObserverManager.cs)

```csharp
public Func<DateTime> ObserverManager<TIdentity, GetDateTime
```

Gets or sets the delegate used to get the date and time, for expiry.

## Observers {#observers-8b8f3399}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.utilities.observermanager-2/properties/observers-8b8f3399/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core/Utils/ObserverManager.cs#L93)

```csharp
public IReadOnlyDictionary<TIdentity, TObserver> ObserverManager<TIdentity, Observers
```

Gets a copy of the observers.